tevent: An event system based on the talloc memory management library. (source)

Tevent is an event system based on the talloc memory management library. It is the core event system used in Samba.
The low level tevent has support for many event types, including timers, signals, and the classic file descriptor events.
Tevent also provide helpers to deal with asynchronous code providing the tevent_req (tevent request) functions.